We plan to study (1) the action of phosphorylase kinase and protein kinase on peptide substrates to establish specificity requirements of these enzymes (2) the attachment of active site reagments derived from peptides to phosphorylase kinase (3) the steady state kinetics of the reaction catalyzed by phosphorylase kinase (4) the allosteric function of phosphorylase by the use of peptides (5) the action of pyridoxal and analogs of vitamin B6 on the structure and function of glycogen phosphorylase (6) the specificity of phosphorylase phosphatase on peptide substrates. We hope to establish important factors that are involved in the regulation of enzymic interconversion. Bibliographic references: D.J. Graves, g.M. Carlson, J.R. Skuster, R.F. Parrish, T.J. Carty and G.W. Tessmer, "Pyridoxal Phosphate-dependent Conformational States of Glycogen Phosphorylase as Probed by Interconverting Enzymes," J. Biol. Chem. 250, 2254-2258 (1975). T.J. Carty, Jan-I Tu and D.J. Graves, "Regulation of Glycogen Phosphorylase. Role of the Peptide Region Surrounding the Phosphoserine Residue in Determining Enzyme Properties," J. Biol. Chem. 250, 4980-4985 (1975).